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O-320 Engine Failure

The engine in my Piper PA-28-161 suddenly failed in the air without warning. The engine could not be restarted.
Thanks to the POC a successful forced landing saved all.
Attempts to restart the engine on the ground were not successful.

Turning the prop by hand produces a clicking sound that seems to be coming from close behind the prop.
Hardly any compression is felt when turning the prop.
Is it possible that the camshaft is not turning with the crank?
I know on this engine gears couple the camshaft to the crankshaft. Is it possible that the gears broke off?
If so will there be damage to the valves? Is this an interference engine?

Claude

Clicks could be the magnetos or the starter gear.But no compression and fan like revolving smells of a broken crankshaft ,right after the prop flange.Hope it is not so dramatic.

LGGG

Ooops! Sounds like the crankshaft, because even if the camshaft is not turning, there would compression somewhere.

When my 0-320 was condemned on cam corrosion (at 2350 hrs) I had to insist that the engineers who were gung-ho for a UK overhaul pulled the core plug in the crankshaft first. Sure enough, the hollow crankshaft just behind the prop was corroded beyond limits. Any rebuild shop would have happily whacked a crankshaft core charge onto the bill.

Happily Lycoming at the time were offering factory rebuilds regardless of core condition. I sent them photos of the crankshaft to avoid misunderstandings and there weren’t any. The exchange engine was installed and flying in 3 weeks and has continued so for 6 years now.

EGBW / KPRC, United Kingdom

Crankshafts rarely break cleanly though. The photos I have seen show breakages which are rough and are at an angle. But it is possible…

Administrator
Shoreham EGKA, United Kingdom
One or more valves stuck open ?? Vic
vic
EDME

Remove a top sparkplug. You should be able to see the piston at its top position. Establish it is moving.
Do cylinder pressure tests. Much cheaper than pulling engine apart.
What happened as the engine stopped? Unusual noise?
Did the prop keep turning, at about the same speed as throttle fully closed?

Maoraigh
EGPE, United Kingdom

Claude wrote:

Thanks to the POC a successful forced landing saved all.

Whats a “POC” ?

FAA A&P/IA
LFPN

Michael wrote:

Whats a “POC” ?

Guess: Mistyping of “PIC”. “I” and “O” are next to each other on the keyboard.

ESKC (Uppsala/Sundbro), Sweden

Yes, it is a mistyped PIC.
Thanks to all who answered.
My mechanic will be going with me to the field to try to find the cause of the failure.

I will keep the group informed.

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